Container



E. R. KELLEY 3,342,400

sept. 19, 1967 CONTAINER Filed Sept. 22, 1965 Z20a Z.Zla

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ATTORNEYS United States Patent O 3,342,400 CONTAINER Ernest R. Kelley, Concord, Calif., assignor to Fibreboard Paper Products Corporation, San Francisco, Calif., a corporation of Deiaware Filed Sept. 22, 1965, Ser. No. 489,130 6 Claims. (Cl. 229-37) This invention relates to a container and more particularly relates to a multi-ply container wherein portions of one of the plies adjacent a container cover flap is removed to improve the stacking strength thereof.

A basic requirement for most containers is that they provide adequate stacking strength to thus resist a tendency to collapse when loads are imposed thereupon. This requirement is particularly important with respect to corrugated, paperboard containers, for example, adapted to contain articles which are prone to crushing. When such containers are filled and stacked, the lowermost containers oftentimes support a considerable weight.

In order to enhance the compression or stacking strength of the container, plies have generally been added to various panel-s thereof. Another well known procedure for increasing stacking strength is to utilize a stronger container material.

This invention departs radically from the above, briefly described, accepted procedures in that the stacking strength of a multi-ply container is enhanced by removing rather than adding material adjacent to a scoreline which hingedly connects a vertically disposed panel to a horizontally disposed cover flap. The initial reaction by one skilled in the art would be that such material removal would function to decrease the stacking strength of the container. However, as will be more fully understood from the following discussions testing has proved that such removal actually increases stacking strength.

An object of this invention is to provide a multi-ply container blank which may be expeditiously erected to form a container which exhibits a greater stacking strength and utilizes less material than conventional ones.

A further object of this invention is to provide a multiply container wherein portions of one of the plies are removed adjacent a scoreline which hingedly connects two panels together to provide means for increasing the 1stacking strength thereof.

Further and more specific objects of this invention will become apparent from the following description and drawing wherein:

FIG. l discloses an erected, multi-ply container;

FIG. 2 is the blank utilized to form the container illustrated in FIG. l;

FIG. 3 is an alternative blank which may be utilized to form the type of container illustrated in FIG. l;

FIG. 4a is an enlarged, cross-sectional View taken in the direction of arrows 45t-4a in FIG. l;

FIG. 4b discloses the corner construction illustrated in FIG. 4a as it would appear after a load has been imposed thereupon; and

FIGS. 5a and 5b illustrate prior art container constructions corresponding to those disclosed in FIGS. 4a and 4b, respectively.

The container illustrated in FIG. l preferably has a rectangular cross-section and is formed out of the multiply blank of FIG. 2. The Iblank preferably comprises an outer facing ply or sheet 10, an intermediate corrugated ply 11 and an inner facing ply 12, all formed of a paperboard constituent. Main body panels 13, 14, 15 and 16 are adapted to be attached together in a conventional manner by means of manufacturers glue ap 17.

A longitudinally extending scoreline 18 hingedly connects top closure r cover flaps 19, 20, 21, and 22 to their ICC respective panel members, adjacent to edge 23 of inner ply 12. Slots are preferably formed between the aps in order to facilitate folding when the container is erected. The flap arrangement for the bottom closure is preferably identical to the flap arrangement for the top closure and is thus denoted by like numerals, accompanied by subscripts a.

Manufacturers glue ilap 17 is secured to panel 16 by means of a conventional adhesive to form a tubular shaped container for shipping purposes. The bottom closure may be formed by attaching flaps 19a-22 together in superimposed relationship by a conventional fastening means, such as an adhesive. After the contents have been placed in the container, flaps 19-22 may be attached together in a like manner to form the top closure. It should be noted that the ccrrugations formed on intermediate ply 11 are preferably arranged vertically when the formed container assumes its normal FIG. 1 position.

The alternative blank arrangement illustrated in FIG. 3 differs from the afore-described blank in that the inner facing sheet is arranged to cover the closure flaps. It should be noted that the numerals in FIG. 3, accompanied :by a prime symbol correspond to the numerals and thus like numbered elements appearing in FIG. 2.

FIGS. 4a and 4b illustrate how the means for enhancing the stacking strength of the container appears to function when a load is imposed upon top ilap 19, for example. As therein indicated, when a load is imposed upon horizontally disposed flap 19, a type of rolling function occurs at the corner with respect to vertically disposed panel 13. Such rolling results in a partial collapse of the panel which is resisted due to the construction and arrangement of the means formed by the arrangement of edge 23 of inner ply 12.

Referring now to the conventional or standard corner construction illustrated in FIGS. 5a and 5b, it can be seen that when a load is imposed upon the top panel thereof that the paperboard undergoes a severe crushing with the inner ply undergoing a fold of approximately Various tests were conducted to compare this type of prior art con-struction to that illustrated in FIG. 4a'.

For example, a conventional corrugated container having a size of 27 in. x 13 in. x 71/2 in. was subjected to top loading and exhibited a compression strength of approximately 1180 pounds before collapse. In comparison thereto, a similarly sized container having edge 23 of liner 12 spaced one-quarter of an inch from scoreline 18 (H1), exhibited a compression strength of 1658 pounds, i.e., a 40% increase in compression or stacking strength over the tested standard container. In addition, a .51 pound savings in the amount of inner liner 12 utilized was realized. Additional comparative tests on containers of various sizes further indicated that application of the inventive principles herein taught gave rise to a number of new and unexpected results.

The following chart lists the results of a number of such comparative tests, conducted upon three-ply corrugated paperboard containers. Tested containers of t-his invention were formed out of blanks similar to those disclosed in FIGS. 2 and 3.

The Size column lists the containers length, width and internal height (H2), respectively. The Grade notation-s for the paperboard utilized are standard ones, well known to those skilled in the packaging arts. For example, the numeral 275 denotes the results of a standard Mullen test conducted according to the Uniform Freight Classification, Rule 41, Section 3. The letter A symbolizes that thirty-six standard flutes or corrugations on ply 11 were employed per linear foot whereas the letter C symbolizes that forty-two such flutes were utilized.

The Compression or stacking strength may be generally deiined as the amount of top load (1b.) the container withstood before substantial collapse.

AVERAGE MAXIMUM TOP LOAD COMPRESSION (LB.)

container size (in.) ill/H2 Grade comp. str. Svlgs (approx.) Str. (lb.) Inc. 12 (1b) standard 27 x13 x 7.5 275-15.-- 1,180 r11=25111 27 x 13 x 7.5 3. 33% 275-A.- 1, 55s 40% .51 Standard 26 75 x 13 x 7 5 275A 1,180 H1=.125 m 25.75 X 13 x 7 27s-A--- 1, 445 28% 51 H1=.25 in 25.75 x 13 X 7. 275-5.- 1,577 39% .51 standard--- 21 x 15 X 22.- 175-A--- 750 H1=.1251n 24 x 15 x 22 1751-5,.-- 577 25% .42 standard 25.5 x 15.5 x 22.5. 175-A.-. 819 111:.125 in.- 25.5 x 15.5 x 22.5... 175-A.-. 984 20% .54 standard 17.5 X 11.5 X 11.125. 2004: 511 H1=.25 1n 17.5 X 11.5 X 11.125. 205C 751 12% .25 standard.-. 15 x 14.25 x 19.5--.. 175-11--- 514 H1=.251n 15 x 14.25 x 19.5.--- 175- Referring once again to FIG. 2, the vertical height of the area between edge 23 of ply 12 and the center of scoreline 18 is depicted by H1 whereas the vertically disposed height of a panel between parallel scorelines 18 and 18a is depicted by H2. Testing has shown that it is desirable to maintain H1 from 0.1% to 20% of H2 and preferably from 0.4% to 5%. The distance H1 may be from 0.0625 in. to 0.5 in. and preferably from 0.125 in. to 0.25 in.

It should be noted that the above discussed inventive concepts may be also applied to a large number of noncorrugated containers having two or more plies. Also, a material other than paperboard may be utilized therefor and the container may have a non-rectangular cross-section, i.e., hexagonal, octagonal, etc. Furthermore, the means for increasing stacking strength (H1) may be formed on any one of the container plies, .although it is preferable that the same be formed on the inner ply, i.e., -such as inner ply 12 of the container illustrated in FIG. l.

I claim:

1. A corrugated container comprising superimposed outer, intermediate and inner plies forming horizontally disposed top and bottom closure aps and vertically disposed panels, outer and inner intermediate plies substantially arranged in coextensive relationship, said inner ply arranged on said panels to terminate short of a scoreline hingedly connecting said top closure flaps to said panels, said inner ply being absent for a distance from said termination at least to said scoreline so that said panels resist crushing when a load is imposed upon said top closure thereby increasing the container stacking strength.

2. The invention of claim 1 wherein the distance from the point where said inner ply terminates to said scor'eline is from 0.0625 in. to I0.5 in.

3. The invention of claim 1 wherein the distance from the point where said inner ply terminates to said scoreline is from 0.125 in. to 0.25 in.

5. A multiply corrugated blank comprising a series of connected panels and a scoreline formed on said panels dening a Ailap arranged to extend from each of said panels, said flaps adapted to be formed into a container top closure, said panels comprising outer, intermediate and inner plies, said outer and intermediate plies arranged in substantial coeXtensive relationship, said inner ply arranged to terminate short of said scoreline and be absent for a distance at least to said scoreline so that said panels resist crushing when a load is imposed upon said top closure and the stacking strength is increased when the blank is erected.

6. The invention of claim 5 wherein said aps constitute outer, intermediate and inner plies.

References Cited UNITED STATES PATENTS 1,708,700 4/ 1929 Moier 229-37 1,912,698 4/ 1933 Forsman 229-37 1,973,930 911934 Rammer 229-14 1,987,225 1/ 1935 Bergstein.

2,710,134 6/ 1955 Schroeder et al. 229-37 2,857,091 10/1958 Enzie 229-37 2,878,982 3/1959 Gariepy 229-14 2,949,151 8/1960' Goldstein.

3,199,763 -8/ 1965 Anderson.

FOREIGN PATENTS 534,925 2/1955- Belgium. 1,367,690 6/ 1964 France.

JOSEPH R. LECLAIR, Primary Examiner.

DAVIS T. MOORHEAD, Assistant Examiner. 

1. A CORRUGATED CONTAINER COMPRISING SUPERIMPOSED OUTER, INTERMEDIATE AND INNER PLIES FORMING HORIZONTALLY DISPOSED TOP AND BOTTOM CLOSURE FLALPS AND VERTICALLY DISPOSED PANELS, OUTER AND INNER INTERMEDIATE PLIES SUBSTANTIALLY ARRANGED IN COEXTENSIVE RELATIONSHIP, SAID INNER PLY ARRANGED ON SAID PANELS TO TERMINATE SHORT OF A SCORELINE HINGEDLY CONNECTING SAID TOP CLOSURE FLAPS TO SAID PANELS, SAID INNER PLY BEING ABSENT FOR A DISTANCE FROM SAID TERMINATION AT LEAST TO SAID SCORELINE SO THAT SAID PANELS RESIST CRUSHING WHEN A LOAD IS IMPOSED UPON SAID TOP CLOSURE THEREBY INCREASING THE CONTAINER STACKING STRENGTH. 